How can a pleural process be differentiated from an extrapleural process? List five differential diagnoses for multiple pleural densities. List four differential diagnoses for an extrapleural mass. Book traversal links for Pleural mass ‹ What is the minimum amount of fluid needed to detect a pleural effusion on a lateral film and a frontal film, respectively? Up How can a pleural process be differentiated from an extrapleural process? ›